coala.bin: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/coala.bin - from package: coala

You may install the required package with command apt-get install {package}

Error in other languages:
coala.bin: bevel nie gevind nie
coala.bin: comandă negăsită
coala.bin: comando não encontrado
coala.bin: commande introuvable
coala.bin: command not found
coala.bin: käsku ei ole
coala.bin: không tìm thấy lệnh
coala.bin: komanda nerasta
coala.bin: Kommando nicht gefunden.
coala.bin: kommandot finns inte
coala.bin: komut yok
coala.bin: nie znaleziono polecenia
coala.bin: níor aimsíodh an t-ordú
coala.bin: no se encontró la orden
coala.bin: no s'ha trobat l'ordre
coala.bin: opdracht niet gevonden
coala.bin: parancs nem található
coala.bin: perintah tidak ditemukan
coala.bin: príkaz nenájdený
coala.bin: příkaz nenalezen
coala.bin: команда не найдена
coala.bin: командата не е открита
coala.bin: 命令找不到
coala.bin: コマンドが見つかりません